Can stress cause colds and flu?

It's winter, and like every year colds and flu are doing the rounds. Why, however, do some people turn into snivelling wrecks while others remain largely unaffected?

What we do know is that disease tends to strike when we’re suffering from stress, and according to a Health24 article, you know you're stressed if you're suffering from some or all of the following symptoms:

Headaches

Disturbed sleep

Feelings of anxiety

Tension

Irrational and inappropriate bursts of anger and aggression

Concentration problems

Depression

Increased or decreased appetite

Bhekisisa reminds us that every day, an estimated
21 South Africans commit suicide and that, according to experts, stress could
be a significant contributing factor.

And according to the Anxiety and Depression Association of
America, people exposed to chronic stress have shorter telomeres
(the "caps" at the end of each strand of DNA that protect our
chromosomes) in their white blood cells, which leads to ageing and shorter lifespans.

'Fight or flight'

Until not so long ago, most stressful situations or threats in life required physical action – for example when confronted by a hungry lion or members of an enemy tribe we had the choice of running away or facing the danger. This is called the "fight or flight" reaction.

Nowadays, even though stressful situations like losing your job or not being able to pay the mortgage don’t require a physical response, our bodies don't know the difference, and we still react the way our forefathers did by automatically releasing stress hormones like cortisol and adrenaline.

The effect is that the body focuses all its energy on fighting or fleeing and shuts down other physical processes like digestion, even though physical action is not required.

A physical threat usually passes quite quickly, and assuming you survived the onslaught, your body returns to normal. In the case of psychological stress, however, the situation may take weeks or even months to resolve, leaving the body in a constant state of low-level stress.

Compromised immunity

One of the vital systems that is suppressed in a fight or flight situation is the immune system, which is designed to protect us against attacks from bacteria and viruses that cause illnesses like the flu.

Health24's CyberShrink
agrees that psychological stress can indeed contribute to a state where one's physical
level of resistance is lower than usual. He adds that the reverse is also true, and that a physical ailment can cause mental stress.

The bottom line, therefore, is that although (most) colds and flu are caused by viruses, the body only succumbs to such attacks when our immunity is compromised by, among other things, stress.